Well plug



ugg 8 1944 R. BAsslNGER 21,355,199

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WELL PLUG Filed May 6. 1940 '2 Sheets-Sheet 24 sa 55 se T50 t: 46T 52 ggz l 30 I9 .56 zo 3l .57

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la ze 6* f 16 65 j 6? 65 9 9 @g55 @A55/N55@ C??? 9 LW @we/14M' PatentedAug. 8, 1944 UNITED sTATEs- PATENT oFFlcE WELL PLUG Ross Basslnger,Houston, Tex. Application May 6, 1940, serial N0.,333,ss4

7 Claims.

, This invention relates to new and useful improvements in well plugs.

-One object of this invention is to provide an improved well plug whichmay be quickly and readily set in a well bore; and which is arranged toprevent the accidental or premature setting thereof.

An important object of the invention is to provide an improved well plugwhich is so arranged that' any fluid pressure acting upwardly againstthe plug, after the latter has been set in the well bore, will tend tofurther distort the packing means and increase the set of the slipmeans, whereby the plug will not be loosened in the Well bore or causedto leak by the pressure fluid.

A further object of the invention is to provide an improved well plugwhich is formed in its entirety of readily drillable material, andwherein means is provided for holding the various elements againstrotation during the drilling operation so that, when desired, the plugmay be drilled out and circulated out of the well bore by means of thedrilling uid.

A still further object of the invention is to provide an improved wellplug adapted to be lowered into the well bore upon a tubing string, andto be set by the rotation of said tubing, and which may be used as acement retainer, a flow packer, and a bridge plug.

Still another object of the invention is to provide an improved wellplug which is constructed of a minimum number of parts, whereby themanufacture of the plug is rendered less difficult and expensive, andthe operation of the plug is simplified and made more eflicient andpositive.

A further object of the invention is to provide an improved well plughaving a frangible slip member arranged to be readily broken intosections when engaged by a drill in drilling up the plug.

Still another object of the invention is to provide an improved shoe fora well plug arranged to anchor the plug in the well bore when cemented.

Another object of the invention is to provide an improved well plug,wherein the means for holdingv the plug against rotation is disposed atthe lower extremity thereof, so as tohold the elements abovesaid meansagainst rotationrwhile they are being drilled up.

which an example of the invention is shown, and wherein:

Figure 1 ls a longitudinal sectional view of a well plug constructed inaccordance with the invention, showing the plug as it is lowered intothe well bore,

Figure 2 is a view similar toFlg-ure 1, showing the well plug set in thewell bore,

Figure 3 is a horizontal, cross-sectional view taken on the line 3'-3 ofFigure 1,

Figure 4 is a horizontal, cross-sectional view taken on the line 4-4 ofFigure 1,`

Figure 5 is a horizontal, cross-sectional view taken on the line 5-5 ofFigure 1,

Figure 6 is a horizontal, cross-sectional View taken on the line 6 6 ofFigure 1,

Figure 7 is a horizontal, cross-sectional view taken on the line 'l-l ofFigure 11,

Figure 8 is a horizontal, cross-sectional view taken on the line 8-8 ofboth Figures 1 and 11,

Figure 9 is a horizontal, cross-sectional view taken on the l'lne 9-9 ofFigure 11,

Figure 10 is an isometric view of the lower portion of the plug, showingthe construction of the wall-engaging dogs, and the anchoring member,

and

Figure 11 is a longitudinal, sectional view of arwell plug, constructedin accordance with a modification of the invention.

In the drawings, the numeral I0 designates an elongate tubular mandrelor actuating element which has an axial bore II extending therethrough.The lower portion of the mandrel is slightly reduced and provided withexternal screwy threads I2. f The mandrel telescopes the sleeve or shankI3 of an annular shoe I4, the shank and sleeve forming a support. Thesleeve I3 is provided with an axial bore I5 which terminates at itslower end at an annular shoulder I6 formed at the upper end of anenlarged axial bore I'Ivin the shoe. A short distance above the shoulderI6 the bore I5 of the sleeve is formed with an annular boss or nut I8which is internally screw-threaded to receive the screw threads I2 ofthe mandrel, so that when the mandrel is rotated, it will be" movedlongitudinally in the bore of the sleeve. In order to pack oli? thesleeve and mandrel, an annular recess I9 is provided in the upper end ofthe bore l5 of the sleeve, and receives an annular, pressure-sealing,packing ring 20 which has an internal diameter of such size as to permitthe screw threads I2 to pass freely therethrough, but to snugly engagearound the in Figure 2.

'I'he shoe l 4 is provided with a plurality of elongate, radial,vertical recesses 2| in which suitf able back-ofi` dogs 22 are mounted.The dogs are secured by pins 23 which extend longitudinally of therecesses, said dogs being adapted to swing into engagement with theinside wall of. the casing A upon clockwise rotation of the plug. Eachof the dogs 22 carries vertical gripping teeth 24 upon its outer end,said teeth being so designed as to resist right-hand rotation of thesleeve. A horizontal groove 25 extends backwardly from each of. therecesses, and a short coil spring 26 is positioned in each ofthegrooves. One end of each of the springs 26 is secured to the shoe Itwithin one of the groovesv25 while the other end of each spring issecured to one of the dogs. Since the springs are under tension, theyact to urge the dogs'and the teeth constantly into engagement with thewall of the casing. Itis pointed out that the teeth 24 are designed toallow vertical movement of the dogs, while .resisting and substantiallypreventing lateral or rotative movement of the latter. Obviously,counterclockwise or left-hand rotation of the sleeve will cause the dogsto swing inwardly .out of engagement with the casing A.

The -upper portion of the shoe i4 forms an outwardly-directed annularshoulder 2l above the back-oil dogs, and an upwardly-directed annularange 28 is provided on the outer edge thereof. A plurality of suitableresilient packing rings 29 rest upon the shoulder within the ange andsurround the shank i3. A slip-actuating or setting member 30 restsupon-the upper end of the uppermost packing ring, which is spaceddownwardly from the upper end of the shank i3. The member 39 issubstantially frusta-conical in contour, and is provided at its lowerportion with an enlarged, axial, circular counterbore 3 l. The bore isof sumcient diameter to receive the upper end of the shank and extendsupwardly some distance into the member. A bore 32 extends upwardly fromthe counterbore throughout the remainder of the member, and is ofsumcient diameter to receive the mandrel i9.

A plurality of circular longitudinal bores 33 extend downwardly from theupper end of the member to the counterbore 3l thereof and are spacedradially about the bore 32. Each of the bores 33 is provided with anaxial counterbore 34. A bolt 35 is disposed in each of the bores 33 soas to have the enlarged head 36 of the bolt disposed in the counterbores34, while the lower screw-threaded end 37 of the bolt extends into thecounterbore 3l. A plurality ofv longitudinal, internally screwthreaded,Acircular recesses 38 are provided about the upper end of the sleeve, andare adaptedvto receive the lower screw-threaded ends 31 of the bolts 35.Thus, the engagement of the \boltheads 3,6 vwithin the recesses 33limits the upward travel of-the slip-actuating inember 3U with respectto the shank i3 and the mandrel l ll, but allows the shank l 3 to travelupwardly within the counterbore 3l as shown in Figure 2.

A split slip or pipe-gripping member. 39 rests upon the member 39, andis provided with the usual external casing-engaging teeth 40. The teeth49 are adapted to engage the inside wall oi the casing A, and preventthe upward or downward movement of the well plug with respect thereto.The slip member is formed with an axial inverted frusto-conical bowl 4|which'is complementary to, and adapted to be engaged by, theconical-shaped member 30. In the unset Positie@ shown in Figure 1, theupper end of the member.y

39 extends into the bowl 4 I.

An annular groove 42, substantially circular in r cross-section, isformed in the outside wall of the slip member, and encircles the latterin ahorizontal plane at a point spaced above the lower-.end thereof. Acoil garter spring 43 is positioned within the groove 42 and surroundsthe slip member so as to compress the latter. lAs will be noted in thedrawings, the outside diameter of the slip member is slightly less thanthe outside diameter of the other elements of the plug, so that as theplug is lowered into the well bore, there will be no possibility of theslip member contacting the inside wall of the casing and accidentallysetting the plug. Also, the garter spring 93, together with the inherentresiliency of the slip member, will serve to hold the member in acontracted position, so that the possibility of accidentally setting theplug by allowing the slip member to engage the casing wall iseliminated.

As is shown in Figures 4 and 6, a number of longitudinal grooves 49 areprovided upon the face of the slip member 39. When the plug is set inthe well bore, as will be hereinafter described, the engagement of themember 39 with the slip member 39 will exert an expanding force upon theslip member. Under'these conditions, the grooves V4t will allow themember 39 to break up into longitudinal sections which may be readilymilled and circulated out of the Well bore. A radial recess or groove 45is formed in the upper end of the member and extends from the insidewall of th bowl to the teeth.

A bearing block 46, having an enlarged circular recess 4T formed in itsbottom, rests upon the upper end of the slip member 39, and is disposedbeneath an annular shoulder 48 formed upon the upper portion of themandrel i9. The block 46 is provided with an axial bore 49 for receivingthe mandrel. An upstanding marginal flange 50 is provided on the upperend of the block, and is contiguous to the periphery of the shoulder 49.An annular race 5l is formed in the upper end of the bearing blockbetween the flange 59 and the upper portion of the bore 49. A pluralityof bearing balls`52 are disposed in the race 5l and have their uppersides engaging in a race 53 formed in the lower side of the shoulder 98.In addition, a pin 54 extends downwardly from the lower side of thebearing block, and engages in the groove 45. The pin 54 serves to holdthe bearing. blockl against any appreciable rotative movement withrespect to the slip member 39..

The mandrelY has its upper end 55 formed integral with the lower end ofthe sleeve of a clutch device, such as is shown in my co-pendingaprplication led February 5, 1940, Serial No. 317,232, now Patent No.2,317,021, granted April 20, 1943,

and which it is not considered'necessary, to ile lustrate herein;however, 'any tool suitable for the purpose may be connected to theupper end of the` rectangular plates or blades 58joined along-one commonvertical edge and equiangularlydisplaced from one another, is secured bymeans of pins 59.\within three radial slots 60 formed in the shoe I4 andequiangularly displaced from one another. Each of thepins 59 passeshorizontally through'the shoe and one of the blades 58 (Figure 3), sothat the member 51 is securely held in position. l'I'he lower portion ofthe anchoring member projects some distance below the lower end of theshoe for reasons to be set forth hereinafter. As is shown in Figures 1and 2, the bore I1 continues downwardly some distance into the anchoringmember and terminates at a point short of the lower end of the member.communication through lsaid bore with the space below the shoe ismaintained.

A suitable valve ball 6I is positioned within the bore I'I. An annularspider 82, having an axial ball seat 63 has a snug sliding t inthe boreI1 below the shoulder I6, which arrests said spider at the upper end ofits movement. The frictional engagement ofthe spider with the bore I'Iis suiilcient to hold the spider in position, but allows the spider tobe forced downwardly in said bore. The seat 63 is of suillcient diameterto accommodate the lower end 64 of the mandrel, which is reduced so asto telescope said seat. It is pointed out that the valve ball 6I willrest in the anchoring member 51 when the plug is assembled, but when theplug is lowered into the well bore the ball will' be forcedupwardlyagainst the spider 62 by the iluid present within said Thus,

bore. The mandrel has an annular beveled valve seat 55 formed on'itslower end for the valve ball 5I to seat against. When the device is inits set position, the ball will engage the valve seat l65 to preventiluid from owing upwardly through the mandrel.

The setting of the plug is simply and easily carried out. The plug issuspended from a string of tubing (not shown), and lowered into the wellbore; the well fluid present therein will flow upwardly around the ball6I and through ther spider 62. The bolts 35 will hold the slip-actuatingmember down upon the shank I3. The well uid flowing upwardly, past themember 30, might tend to raise the member and cause it to expand theslipmember 39 into a setting position. Also, the frictional drag of thepacking rings 29 against the casing wall, or the encountering of trashand foreign material in the well bore, would sometimes be sufficient toset the slip member and the plug prematurely. The bolts securely holdthe member against upward movement and thereby eliminate thesepossibilities.

' -When the desired point is reached in the well bore, the plug isrotated (by means of the tubing string) in a clockwise direction,thereby allowing the springs 26 to pull the dogs 22 into engage l mentwith the inside Wall of the Well casing A.

In this position, the dogs prevent further rotation of the shoe vI4` andshank I3, and force the mandrel to screw downwardly within thescrewthreaded boss I8 of said shank. As the mandrel continues to rotate,and screw downwardly within the bore of the shank, it. forces the shank,

along with the packing rings 29 and the slipber securely. When the slipmember is rmly set,

the continued upward movement of the shank I3 and shoe I4, through therotation of the mandrel, will force the packing rings 29 to distort intoa packed-oil? position, as is shown in Figure 2. At the same time, theupper unthreaded portion of the mandrel I0 will move into`contact withthe packing ring 20, thereby positively sealing of! all avenues ofescape up the well bore with the exception of the bore II of themandrel. Thus the -zug is set positively and very snugly in thewellThere are many instances in the petroleum industry in which this wellplug may be used to advantage. One of the most advantageous uses of theplug is as a cement retainer. In this instance, the plug is set in thewell bore as hereinbefore set forth. It is pointed out that as the plugis lowered into the well, the ball 6I will ride against the spider 62,due to the upward ow of the well fluid past the plug, but will not shutoff the flow of the well fluid upwardly through the bore II of themandrel Ill because of theopen construction of said spider. After theplug has been set, the cement may be pumped down the bore of thetublngthrough the bore II of the mandrel, into the well hole. As isshown in Figure 2, in the set position of the plug, the lower reducedend 64 of the mandrel will extend through the opening of the spider sothat the ball 6I s eats upon the ball seat 65Hformed thereupon. Thefrictional engagement of the spider within the bore Il allows the formerto be forced downwardly by the mandrel as the plug is. set. The ballwill seat upon the seat 65 and will acty 1 as a back-pressure valveduring and after the cement pumping operation. As will be noted, thepresence of fluid pressure beneath the plug may in no way cause the plugto loose or slip. Any upward motion of the plug will cause the member 30to wedge more securely beneath the slip member 39, thus setting the slipmember more securely. It is also pointed out that any desirable degreeof settingvof the plug may be obtained by placing tension upon themandrel through the tubing string. Obviously, upward movement of themandrel will set the slip member more securely, and distort the packingrings 29 to a. more tightly packed-off position. Il. desired, a valveball (not shown) may be dropped down the bore of the tubing so as toseat upon the ball seat 56, thereby shutting off communication with thebore II of the mandrel I0. Any suitable type of washdown anddisconnectingV means may be positioned above the plug.

When it becomes desirable to drill out the plug and circulate thecuttings out of the well bore, the operation is readily accomplished,due to the fact that the entire plug may be formed of drillablematerial. It will be noted that the dogs 22 are situated in thelowerendfy of the plug so that the upper portion of the plug will beheld against rotation as it is drilled out.

Also, the anchoring member 51 is firmly embedded in cement at thecompletion ofthe cef menting operation. The engagement `of the blades 58in the cement -will hold the entire plug against rotation, even aftervthe dogs have been drilled out.

It is important that all the various elements of the plug be heldagainst rotation during the drilling out operation. If any one elementWas not held against rotation, it might rotatev with the cutting millused and thereby require an excessively long `period of drilling. Forthis reason, this plug has been constructed in such a manner that all ofthe elements are held against rotative movement after the plug 'has beenset in a Well bore. It will be noted that the bolts tubing` string.

I3, will hold said member against rotation, and that the slip member 39is also held against rotation by means of its frlctional engagement withthe member 30 and the inside wall of the casing. The engagement of thepin 54 within the groove 145, of the slip member, holds the bearingblock 46 against rotative movement so that vthe entire outside assemblyof the plug is held against rotation by the dogs 22 and the anchoringmember 51. In this manner, a cement retainer is provided which isreadily and positively set in the well bore, and which may easily bedrilled or milled out when so desired. v A modification of the inventionis shown in Figure 11. This form of the invention is. very similar tothe form described hereinbefore, with the exception that the extremelower end of the bore I1 of the shank I3 is enlarged and'carriesinternal screw .threads 66. The anchoring member 51 is omitted, and isreplaced by a bull-no se plug 61 which is externally screw-threaded toengage in the screw threads 65. Openings 68 -are provided in the nose ofthe plug to establish circulation through the bore Il, and aconioallyshaped helical spring 69 is confined between the plug and thevalve ball 6l, Thus the spring 69 tends to urge the ball constantly`upward into engagement with the spider 62, before the well plug is set,and the Valve seat 65, after the plug is set. In all other respects asto structure and operation, the modified form of the invention issubstantially the same as the first form hereinbefore described.

Other important uses of the wel1 plug. described hereinbefore, are as abridge plug and as a production or flow packer. to use the plug as abridge plug, the plug is set in thefusual manner and a suitable valveelement dropped down the bore of the tubing string so as to rest uponthe ball seat 56. In this manner, ilow is shut oi both upwardly anddownber'39, due to the full iloating construction of the member 30. Themember 30 is not. rigidly connected to any other part of the plug, andis therefore free to remain in position behind the slip member, eventhough the other elements of If it is desired 35, which secure themember 30 to the shank.

The modied form shown in Figure 11 is particularly adapted for use as abridge plug or a flow packer, however the form shown in Figures l to 10,inclusive. may be likewise used, but neither form is limited te suchuse.

The well plug described hereinbefore possesses va'riousother apparentandadvantageous uses and applications, all of which constitute a part ofthis invention.

Various changes, alterations and modifications may be made in the size,shape and arrangement of the herein described elements within the scopeof the appended claims.

What I claim and desire to secure by Letters Patent is: I

l. A well packing device including, a support, an anchor attached tosaid support and having depending anchoring blades, means carried by thesupport for holding the device againstrotation, a packer carried by thesupport, means carried bythe support for expanding the packer andsecuring the device in a well casing, and means engaging and movablelongitudinally of the sup- 4port forA actuating the expanding andsecuring means.

2. A well packing device, including, a support, an anchor attached tosaid support, means carried by the support for holding the deviceagainst rotation, a. packer carried by the support, means carried by thesupport forexpanding the packer and securing the device in a wellcasing, and

the plug may shift their position slightly. Pressure acting from belowthe plug would, lmani-- festly, tend only to set the member 30 moretightly behind the slip member.

Ii the operator desires to use the plug asv a production or flow packer,fthe valve ball `lil is omitted from the completely assembled plug, andthe latter is 'set inthe usual manner. The absence of the valve ballwill allow fluids to flow upwardly through the bore Ii of the mandreland the bore of .the tubing string.' At the same time, the space betweenthe tubing and casing vabove the plug is sealed 01T, so that any :fluidsvpresent therein are prevented from entering the 'If desired, the spider62, and certain other elements unnecessary to the operation of the plugas a production packer, may be omitted from the completed assembly ofthe plug.

means engaging and movable longitudinally of the support for actuatingthe expanding and securing means, said expanding and securing meansIincluding means for holding the packer against upward movement, wherebypremature actuation of .the expanding and securing-means is prevented.

3. A well packing device including, a mandrel, t

a shoe, a sleeve secured to said shoe and attached to said mandrel, apacker carried by the sleeve,l

dogs carried by the shoe for holding the device against rotation, aspider mounted in the sleeve, a valve ball disposed below the spider, avalve seat formed on the lower end of the mandrel and adapted to beengaged by the valve ball, means for securing the device in position,and means for expanding said securing means.

4. A well packing device including, an actuating element having alongitudinal bore, a support movably carried by the actuating element,an anchor attached to the support and having depending anchoring blades,said actuating element and support havingco-acting means for moving saidsupport longitudinally of the element when the means is actuated by saidelement, packing -means mounted externally upon the support,casing-engaging means carried by said support, a

, pipe-gripping means slidably disposed upon and adapted to be expandedinto pipe-gripping position by the setting member, whereby the movementof .the support longitudinally of the actuating element causes expansionof the pipe-gripping meansl and distortion of the packing means.

5. A well packing device lincluding, an actuat-A ing element having alongitudinal bore, a support movably carried by the actuating element,an anchor attached to the support and having depending anchoring blades,said actuating element and support having co-acting means for movingsaid support longitudinally of the element when the means is actuated bysaid element, packing means mounted externally upon the support.casing-engaging means carried by saidA support, pipe-gripping meansdisposed above the packing means and support, and means associated withthe pipe-gripping means movable relative to said support for expandingsaid pipegripping means and distorting said packing means into sealingposition when the support is moved longitudinally of the actuatingelement.

6. A well packing device including, an actuating element having alongitudinal bore, a support movably carried lby the actuating elementvand having an axial bore communicating with the bore of said element,valve means including a valve and aseat member in the bore of thesupport, the seat member having an opening for bypassing iluid upwardlythrough the bores of said support and elements when the valve Ais seatedand the device is beinglowered through a well casing, the element andsupport having co-actlng means for moving said support longitudinally ofsaid element when the means is actuated by the element, packing meansmounted externally upon the support, an anchor attached to the 'suplposition when said support is moved longitudinally of the actuatingelement.

7. A wen packing device including, a support, i

an anchor attached to the support and having depending anchoring blades,means carried by said support for holding the device against rotation, apacker mounted on the support, means carried by said support forexpanding the packer and securing the device in a well casing, meansengaging and movable longitudinally of the support for actuatingtheexpanding and securing means, and anti-friction means associated withthe actuating means and said expanding and securing means for assistingin\moving the latter means into active position. f

' ROSS BASSINGER.

